Image watermarking using polar harmonic transform with parameters in SL(2,R)

In this paper, a novel polar harmonic transform with parameters in SL(2, R) is proposed in order to increase the security of the watermark information. It is named as the Polar Linear Canonical Transform (PLCT) based on the linear canonical transform. Moreover, a watermarking scheme associated with the PLCT is presented, and the simulations are performed to verify the importance of parameters of the PLCT and improve the capabilities of the existing results on the watermarking information's security. The experimental results show that due to the varieties of parameters, if parameters chosen in the extraction process are inconsistent with those used in the embedding process, then the bit error rate is bigger which means it is worse than that of consistent parameters in the two processes. This confirms the fact that parameters of the PLCT have superior security for watermark information. (C) 2014 Elsevier B.V. All rights reserved.